A fast-switching microwave power source backup system and switching method

Abstract

The invention discloses a microwave power source backup system and a switching method capable of rapid switching. The system comprises at least one set of components, which comprises a variable power synthesizer, which comprises a first and a second phase shifter, a first 3dB bridge and an equal power synthesizer; and also comprises a variable power divider, which comprises a third phase shifter, a second 3dB bridge and an equal power divider; an output end of the equal power divider is connected to an input end of the third phase shifter, and another output end is connected to an input end of the second 3dB bridge; an output end of the third phase shifter is connected to an input end of the second 3dB bridge; an output end of the second 3dB bridge is connected to an input end of the first phase shifter; an input end of the first 3dB bridge is connected to an output end of the first phase shifter; an output end of the first 3dB bridge is connected to an input end of the second phase shifter, and a second output end of the first 3dB bridge is connected to an input end of the equal power synthesizer; and an output end of the second phase shifter is connected to another input end of the equal power synthesizer.

Description

Technical Field

[0001] The invention belongs to the technical field of particle accelerators and relates to a microwave power source backup system capable of rapid switching and a switching method. Background Art

[0002] The energy of charged particles in particle accelerators comes from the accelerating electric field, and klystrons are usually used as microwave power sources for accelerators. At present, taking S-band klystrons as an example, their output peak power is generally in the order of tens of megawatts. According to the needs of different accelerators, their power is provided to several accelerating tubes through a microwave transmission system (waveguides are generally used in high-power and high-vacuum environments) to increase the energy of charged particles passing through the tubes. The microwave power that is not used to accelerate charged particles in the accelerating tube is absorbed by the dry load at the output end and converted into heat and carried away by constant temperature water. At present, the mainstream accelerating tubes can utilize about 2 / 3 of the input power, and the remaining 1 / 3 is absorbed by the dry load at the output end, which means that the microwave power of each klystron that is not effectively utilized is about 1 / 3. As we all know, the procurement and operation costs of klystrons are very considerable, and they also account for a considerable proportion of the construction and operation costs of accelerators. If the 1 / 3 of microwave power that is not effectively utilized can be recycled, the number of klystrons required can be reduced by about 1 / 4. It also means that there is no need to use dry loads, which are relatively expensive in waveguide devices. Waveguides are passive devices with low cost, long life and no need for additional maintenance. Overall, the recycling of microwave power at the output of the accelerator tube can effectively reduce the construction and operation costs of the accelerator, which is in line with the national policy of reducing energy consumption.

[0003] To solve the problem of recycling microwave power at the output end of the accelerating tube, the power is mainly transmitted to a certain place through a waveguide, and then the two microwave powers are synthesized (multiple synthesis can be cascaded). In some other applications, it is hoped that a single microwave power can be distributed to two devices at the same time in any proportion according to demand, and the power of both channels can be continuously variable between 0 and 1 (0 means that the channel has no power, 1 means that the channel has all power, but the sum of the two powers does not exceed 1). Its essence is to achieve arbitrary power division ratio output of a single microwave power. Because of the reciprocity of waveguide devices, the design methods of the two are the same.

[0004] There is no mature design solution for arbitrary power ratio waveguide power combiner at present, but there is a certain history of research on arbitrary power ratio power divider (not necessarily waveguide structure) in the world. As mentioned earlier, due to the reciprocity of waveguide devices, the design methods of the two are essentially the same.

[0005] According to the survey, no design that can be used in high-power and high-vacuum environments has been found so far for arbitrary power ratio waveguide power dividers. The more mature waveguide switches that can be used in high-power and high-vacuum environments are not only expensive and have high maintenance costs, but can only realize the on and off of two microwave powers, and cannot realize arbitrary power ratios, that is, the power ratio of the two microwave powers cannot be adjusted. Waveguide switches are essential components for microwave power source backup systems that can be quickly switched. If mature waveguide switch components are used to make microwave power source backup systems that can be quickly switched, they are not only expensive and have high maintenance costs, but can only realize the two states of "on" and "off", that is, the power is either all given to the second power source K2 or all given to the first power source K1, and the function of partially compensating the power of power source K2 to power source K1 cannot be realized, and its application is very limited. Therefore, how to design a low-cost, widely applicable, and quickly switchable microwave power source backup system is an urgent problem to be solved. Summary of the invention

[0006] In view of the problems existing in the prior art, the object of the present invention is to provide a microwave power source backup system and a switching method capable of rapid switching.

[0007] The technical solution of the present invention is:

[0008] A fast-switching microwave power source backup system, characterized in that it comprises at least one set of components, wherein the components comprise a variable power distributor and a variable power combiner;

[0009] The variable power synthesizer includes a first phase shifter, a second phase shifter, a first 3dB bridge and an equal power synthesizer; the variable power divider includes a third phase shifter, a second 3dB bridge and an equal power divider;

[0010] One output end of the equal power divider is connected to the input end of the third phase shifter through a waveguide, and the other output end is connected to the first input end of the second 3dB bridge through a waveguide; the input end of the equal power divider is used to receive the output power of the backup microwave power source and divide the input power into two outputs; the output end of the third phase shifter is connected to the second input end of the second 3dB bridge; the first output end of the second 3dB bridge is connected to the input end of the first phase shifter, and the second output end of the second 3dB bridge is used to connect to a downstream device;

[0011] The first input end of the first 3dB bridge is connected to the output end of the first phase shifter via a waveguide, and the second input end of the first 3dB bridge is connected to the input port via a waveguide, for receiving the output power of the main microwave power source; the first output end of the first 3dB bridge is connected to the input end of the second phase shifter via a waveguide, and the second output end of the first 3dB bridge is connected to an input end of the equal power synthesizer via a waveguide; the output end of the second phase shifter is connected to the other input end of the equal power synthesizer via a waveguide, and the output end of the equal power synthesizer is used to connect to a downstream main device;

[0012] The third phase shifter is used to adjust the phase of the input power, so as to control the output power distribution of the two output ends of the second 3dB bridge;

[0013] The first phase shifter is used to adjust the phase of the input power, so as to control the phase difference of the input power at two input ends of the first 3dB bridge;

[0014] The second phase shifter is used to adjust the phase of the input power and then output it to the equal power synthesizer;

[0015] The equal power synthesizer is used for synthesizing two input powers and then outputting them.

[0016] Furthermore, when a plurality of sets of cascaded components are included, the output end of the power combiner in the component of the previous stage is connected to the input end of the power divider in the component of the next stage.

[0017] Furthermore, the equal power divider is used to divide the input power into two power outputs with the same amplitude and phase.

[0018] Furthermore, the phase adjustment range of the first phase shifter can ensure that the input power phase difference between the two input ends of the first 3dB bridge is 0° or 180°, the phase adjustment range of the second phase shifter can ensure that the input power phase difference between the two input ends of the equal power synthesizer is 0°, and the phase adjustment range of the third phase shifter can ensure that the input power phase difference between the two input ends of the second 3dB bridge is continuously adjustable between -90° and 90°.

[0019] A power switching method based on the microwave power source backup system capable of rapid switching, comprising the following steps:

[0020] In a normal working state, by adjusting the variable power distributor and the variable power combiner, the received output power of the standby microwave power source is fully provided to the downstream device, and the received output power of the main microwave power source is fully provided to the downstream main device;

[0021] When it is monitored that the output power of the received main microwave power source decreases, the variable power distributor is adjusted to transfer a part of the output power of the backup microwave power source to the input end of the first phase shifter; the first phase shifter in the variable power synthesizer is adjusted to make the phase difference between the first input and the second input of the first 3dB bridge 0° or 180°, and the second phase shifter is adjusted to make the two power inputs of the equal power synthesizer have the same phase;

[0022] When it is monitored that the output power of the received main microwave power source drops to 0, the variable power distributor is adjusted to transfer all the output power of the backup microwave power source to the input end of the first phase shifter; the first phase shifter in the variable power synthesizer is adjusted to make the phase difference between the first input and the second input of the first 3dB bridge be 0° or 180°, and the second phase shifter is adjusted to make the two powers input to the equal power synthesizer have the same phase.

[0023] The advantages of the present invention are as follows:

[0024] The invention patent with application number 202110191601.5 provides a waveguide power distribution and synthesis method with arbitrary power ratio and a distribution and synthesizer; the two output ports of the magic T used therein ( Figure 1 The non-coplanarity of port 1 and port 2 in the system will cause the subsequent waveguide connection to be complicated and the system processing cost to be high. The present invention has made significant improvements to this structural problem, mainly by using a 3dB bridge to replace the magic T in the old structure, achieving a coplanar structure of the two output ports, simplifying the waveguide connection of the system, and thus greatly reducing the system complexity and processing cost.

[0025] At the same time, after realizing arbitrary power ratio waveguide power distribution and synthesizer, it has great application potential in realizing microwave power source backup system that can be switched quickly. By configuring arbitrary power ratio waveguide power divider at the input end of the second power source K2 and arbitrary power ratio waveguide power synthesizer at the input end of the first power source K1, when the input power of the first power source K1 decreases or is completely lost, the arbitrary power ratio waveguide power divider and synthesizer can be adjusted to quickly transfer part or all of the power of the second power source K2 to the first power source K1 for compensation, ensuring that power is always provided to the downstream equipment of the first power source K1. The entire switching process can be completed in a few minutes. Compared with the current mainstream large scientific facilities, after the failure of the first power source K1, it needs to destroy the vacuum, replace spare parts, draw high vacuum and then aging, and the whole process takes at least 5 days of recovery time. It greatly reduces the failure rate of large scientific facilities such as high-energy accelerators and synchrotron radiation sources, and has great significance and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the magic T.

[0027] Figure 2 This is the structural diagram of the 3dB bridge.

[0028] Figure 3 The schematic diagram and three-dimensional schematic diagram of the arbitrary power ratio waveguide power divider based on 3dB bridge;

[0029] (a) is the schematic diagram, and (b) is the three-dimensional schematic diagram.

[0030] Figure 4 The schematic diagram and three-dimensional schematic diagram of the arbitrary power ratio waveguide power combiner based on 3dB bridge;

[0031] (a) is the schematic diagram, and (b) is the three-dimensional schematic diagram.

[0032] Figure 5 The schematic diagram of the fast-switching microwave power source backup system is shown in FIG.

[0033] Figure 6 A three-dimensional schematic diagram of a fast-switching microwave power source backup system.

[0034] Figure 7 This is the simulation result of arbitrary power ratio waveguide power combiner.

[0035] Figure 8 This is a comparison chart of the theoretical and simulation results of the arbitrary power ratio waveguide power divider.

[0036] Fig. 9 The microwave power propagation patterns obtained from simulations in three cases;

[0037] (a) Normal operation, (b) Partial compensation operation, (c) Full compensation operation. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0039] The invention patent with application number 202110191601.5, "A method and device for distributing and synthesizing power in waveguides with arbitrary power ratio", realizes the power distribution and synthesizer based on the magic T. However, because the two output ports of the magic T are not coplanar (the magic T structure is as follows Figure 1 As shown, the output ports are port 1 and port 2). Whether it is power distribution or synthesis, the waveguide connection after the magic T output will be very complicated.

[0040] Because the magic T is essentially a 180° hybrid bridge, the variable power distribution and synthesis achieved by it can also be achieved using an orthogonal (90°) hybrid bridge in theory. Among the waveguide orthogonal hybrid bridges in high-power and high-vacuum environments, the 3dB bridge (also called a 3dB power divider) is the most commonly used. Its structure is as follows: Figure 2 The 3dB bridge is a coplanar structure. The waveguides passing through it are still in the same plane, which is very convenient for subsequent waveguide connection and installation. It can greatly reduce the number of waveguide components in the entire power distribution and synthesizer, effectively reduce system complexity and significantly reduce system processing costs. At the same time, the space requirements for the overall installation of the system will also be greatly reduced.

[0041] The schematic diagram and 3D schematic diagram of the arbitrary power ratio waveguide power divider based on 3dB bridge are shown in Figure 3 . A single input power is input into the equal power divider from port 1, and then is evenly distributed by the equal power divider into two equal amplitude and same phase output powers. One of the output powers is transmitted from A1 to A2 via a common waveguide as the input of the phase shifter. The phase shifter is used to change the phase of this power (but not the amplitude of this power). After the phase is changed, this power is output from A3 and transmitted to A4 via a common waveguide as the first input of the 3dB bridge. The other output power of the equal power divider is transmitted from B1 to B2 via a common waveguide as the second input of the 3dB bridge. Therefore, the first input of the 3dB bridge at A4 is equal to the second input at B2 in amplitude, but has a certain phase difference (the size of this phase difference is controlled by the phase shifter). By simply controlling this phase difference, any power ratio at the output port 2 and the output port 3 of the 3dB bridge can be achieved. The implementation principle and solution are elaborated in detail later.

[0042] The schematic diagram and 3D schematic diagram of the arbitrary power ratio waveguide power combiner based on 3dB bridge are shown in Figure 4. The first input power at the phase shifter port 1 is output from A1 after being phase shifted by the phase shifter I, and is transmitted to A2 via a common waveguide as the first input of the 3dB bridge. The second input power at port 2 is directly input into the 3dB bridge as the second input of the 3dB bridge. Through the phase shifting of the phase shifter I, the phase difference between the first input and the second input of the 3dB bridge is 0° or 180°. Therefore, no matter what the power amplitude ratio between the first input of the 3dB bridge at A2 and the second input at port 2 is, two output powers with equal amplitudes but different phases can be obtained at the outputs B1 and C1 of the 3dB bridge. The output power of the 3dB bridge at B1 is transmitted to B2 via a common waveguide as the input of phase shifter II. After appropriate phase shifting by phase shifter II (appropriate phase shifting is required to ensure that the phases of the powers at B4 and C2 are the same), it is output from B3 of phase shifter II and transmitted to B4 via a common waveguide as the first input of the equal power synthesizer. The output power of the 3dB bridge at C1 is transmitted to C2 via a common waveguide as the second input of the equal power synthesizer. The function of the equal power synthesizer is to synthesize the first input power at B4 and the second input power at C2 into one power (the powers at B4 and C2 are equal in amplitude and phase) and output it at port 3. This realizes the final synthesis of two input powers with arbitrary power ratio. The implementation principle and solution are elaborated in detail later.

[0043] After the realization of the above-mentioned arbitrary power ratio waveguide power distribution and synthesizer based on 3dB bridge, it has great application potential in realizing a fast-switching microwave power source backup system. The relevant schematic diagram is shown in Figure 5 In various large scientific facilities such as high-energy accelerators and synchrotron radiation sources, the first microwave power source (defined as K1) is often irreplaceable, because K1 generally provides power to the bunching section for the longitudinal bunching of the particle beam. The second power source, the third power source, etc. (defined as K2, K3, etc.) can often be replaced, and even if one or more of them are in backup mode, it will not affect the normal operation of the entire device.

[0044] Therefore, taking K2 as an example, if a variable power divider is used at the input of K2 (port 2), and a variable power combiner is used at the input of K1 (port 1), the first output (port 4) of this variable power divider provides power to the downstream device of K2, and the second output provides power to the variable power combiner at A as the first input of the variable power combiner. The second input of the variable power combiner comes from the input of K1 at port 1, and the total combined power is provided to the downstream device of K1 at port 3.

[0045] Thus, in normal working state, the variable power divider and the variable power combiner can be adjusted so that the input power of K2 at port 2 is all provided to the downstream device of K2 at port 4, and no power goes to A to be provided to the variable power combiner (such as Figure 3 As shown, by adjusting Figure 6 At the same time, all the input power of K1 at port 1 is provided to the downstream device of K1 at port 3 (such as Figure 4 As shown, by adjusting Figure 6 This is achieved by using the phase shifter I and phase shifter II in the figure).

[0046] If the input power of K1 at port 1 decreases due to some fault, the input power of K2 at port 2 can be transferred to A by adjusting the variable power divider and provided to the variable power combiner to compensate for the power amplitude of K1 (such as Figure 3 As shown, by adjusting Figure 6 Then, the variable power combiner is adjusted to combine the power from A with the power from port 1, and then the power is normally provided to the downstream device of K1 at port 3 (such as Figure 4 As shown, by adjusting Figure 6 This is achieved by using the phase shifter I and phase shifter II in the figure).

[0047] In the worst case, if the input power of K1 at port 1 is 0, the input power of K2 at port 2 can be transferred to A by adjusting the variable power divider (the output power of K2 at port 4 is 0 at this time) and provided to the variable power combiner (such as Figure 3 As shown, by adjusting Figure 6 Then, the power from A is provided to the downstream device of K1 (such as Figure 4 As shown, by adjusting Figure 6 The above assumes that the output power level of each power source is equivalent, which is a reasonable assumption for large scientific devices that use the same klystron as microwave power source. At the same time, when adjusting the variable power synthesizer at any time, the phase shifter I should be used to make the phase difference between the two input powers at B and C be 0° or 180° (such as Figure 4 As shown), the variable power combiner can successfully combine the two input powers.

[0048] The above design can ensure that the downstream device of K1 at port 3 always has power fed in, which is very important for large scientific facilities such as high-energy accelerators and synchrotron radiation sources that require extremely low failure rates. Because the K1 and K2 power sources are always in operation, when K1 fails, part or all of K2's power will be transferred to K1's downstream devices for use, which is equivalent to using K2 as a hot backup for K1. This power switching only requires adjusting Figure 6 Phase shifter I, phase shifter II and phase shifter III can control the propagation direction of microwave power through appropriate phases. The entire switching process can be completed in a few minutes. Compared with the current mainstream large scientific equipment, which needs to destroy the vacuum, replace spare parts, pump high vacuum and then aging after K1 failure, and the whole process takes at least 5 days of recovery time, it greatly reduces the overall failure time of the device (that is, reduces the failure rate) and increases the available time of the device, which is of great significance. The faulty K1 power source can be replaced during the annual routine shutdown maintenance period, without occupying precious operating time. At the same time, this design does not affect the normal operation of providing power to respective downstream devices at ports 3 and 4 respectively when the K1 input power at port 1 and the K2 input power at port 2 are normal.

[0049] The present invention Figure 6 The scheme of "fast-switching microwave power source backup system" is as follows: a variable power divider is configured at the K2 input of port 2, a variable power combiner is configured at the K1 input of port 1, and one of the outputs of the variable power divider is used as one of the inputs of the variable power combiner ( Figure 6 Finally, when the input power of K1 at port 1 decreases, the input power of K2 at port 2 is quickly switched to compensate, so that the output power of K1 at port 3 always meets the requirements and the downstream equipment of K1 has sufficient power available. This solution adjusts the phase shifter ( Figure 6 Phase shifters I, II and III in the control circuit can be used to control the microwave phase and thus the direction of microwave propagation, thereby achieving the required power distribution and synthesis. The power can be input to K1 at port 1 ( Figure 6 ) partially drops or completely drops to 0, the K2 input power at port 2 ( Figure 6 ) Part or all of the power is transferred to K1. Compared with the current mainstream large scientific equipment, after the failure of K1, it needs to destroy the vacuum, replace spare parts, pump high vacuum and then refrigerate, and the whole process takes at least 5 days to recover. This greatly reduces the failure rate of large scientific equipment and ensures the operation time.

[0050] Feasibility Proof:

[0051] 1) Derivation of theoretical formula (feasibility proof of implementation scheme of coplanar arbitrary power ratio waveguide power distribution and synthesizer based on 3dB bridge):

[0052] based on Figure 2 Port definition, assuming that the microwave input to port 1 is Port 2 input microwave is Then the output of port 3 and port 4 is as follows (E and are the amplitude and phase of the input microwave respectively):

[0053]

[0054]

[0055] If E1=αE2, where α∈(0,+∞), and let E2=1.

[0056] At the same time θ is the phase difference between the input microwaves at port 1 and port 2, then equations (1) and (2) become:

[0057]

[0058]

[0059] Use the auxiliary angle formula to find the modulus of equations (3) and (4) and make them equal, then we have

[0060]

[0061] Formula (5) can be simplified as:

[0062] 2α×sinθ=-2α×sinθ,α∈(0,+∞) (6)

[0063] The condition for formula (6) to always hold is sinθ≡0, that is, θ=0° or 180°.

[0064] This means that when sinθ≡0, that is, θ=0° or 180°, for any input power ratio of port 1 to port 2 Both can achieve 1:1 power split (different phase) output of port 3 and port 4. Then, just need to shift the phase of any output and then use an equal power combiner to complete the final synthesis of two microwave powers with any input power ratio. For the waveguide power combiner with any input power ratio, its implementation block diagram is as follows: Figure 4 shown.

[0065] At the same time, if the input microwave power amplitudes of port 1 and port 2 are equal, there is only one phase difference θ, that is, E1 = αE2, (α = 1) and Substituting it into equations (3) and (4) and using the auxiliary angle formula to calculate the modulus and simplify it, the ratio of the output microwave power amplitudes of port 3 and port 4 is:

[0066]

[0067] It is not difficult to see that when When , the value range of formula (7) is (0, +∞). That is, if an equal power divider is used to divide a certain microwave power into equal parts and then output them with equal amplitude and phase, it is only necessary to perform a phase shift within 180° on one of the microwaves, and then input the two microwaves with equal amplitude and different phases into port 1 and port 2 of the 3dB bridge, and then any power ratio output can be achieved at port 3 and port 4 of the 3dB bridge, thus achieving any proportion distribution of the single microwave power. The implementation block diagram is shown in the following figure. Figure 3 shown.

[0068] 2) Computer simulation:

[0069] a) Simulation verification of arbitrary power ratio waveguide power combiner:

[0070] right Figure 2 The 3dB bridge shown is modeled in the software, the phase difference between input port 1 and port 2 is set to 0° (in phase), and the amplitude ratio changes from 0.01→100. At this time, the output amplitude ratio between port 3 and port 4 is always 1:1, which is consistent with the conclusion of formula (6). The simulation results are shown in Figure 7 It should be noted that the output amplitude ratio of port 3 and port 4 in the simulation results has an error of less than 1.5 ten thousandths compared with the theoretical value of 1:1, which is mainly due to the slight difference between the physical simulation model of the 3dB bridge and the ideal situation assumed in the theoretical derivation. In actual simulation, since the number of grids cannot be infinite (so the simulation error can only approach but cannot be 0), the ports of the 3dB bridge cannot be perfectly matched or perfectly isolated.

[0071] b) Simulation verification of arbitrary power ratio waveguide power divider:

[0072] Set in software Figure 2 The amplitude ratio of input port 1 to port 2 is 1:1 (equal amplitude), and the phase difference changes from -90° to 90°. At this time, the output amplitude of port 4 accounts for a continuously variable proportion of the total output from 100% to 0%, which is consistent with the conclusion of formula (7). The simulation results are shown in Figure 8 .

[0073] c) Simulation verification of fast-switching microwave power source backup system:

[0074] like Figure 6As shown, a variable power divider is used at the input end (port 2) of K2, and a variable power combiner is used at the input end (port 1) of K1. The first output (port 4) of this variable power divider provides power to the downstream device of K2, and the second output provides power to the variable power combiner at A as the first input of the variable power combiner. The second input of the variable power combiner comes from the input of K1 at port 1, and the total combined power is provided to the downstream device of K1 at port 3. Ports 1-4 are each equipped with a power monitoring device to measure the actual power value at each port.

[0075] i. In normal working state, the variable power divider and the variable power combiner can be adjusted so that the input power of K2 at port 2 is all provided to the downstream device of K2 at port 4, and no power goes to A to provide to the variable power combiner (such as Figure 3 , can be adjusted Figure 6 At the same time, all the input power of K1 at port 1 is provided to the downstream device of K1 at port 3 (such as Figure 4 , can be adjusted Figure 6 This is called "normal operation".

[0076] ii. When the power monitoring device at port 1 measures the input power of K1 to decrease, the variable power divider can be adjusted to transfer part of the input power of K2 at port 2 to A and provide it to the variable power combiner to compensate for the power amplitude of K1 decrease (such as Figure 3 , can be adjusted Figure 6 Then, the variable power combiner is adjusted to combine the power from A with the power from port 1, and then the power is normally provided to the downstream device of K1 at port 3 (such as Figure 4 , can be adjusted Figure 6 The output power of K1 at port 3 is determined by the measured value of the power monitoring device at port 3 to see whether it meets the requirement. This is called "partial compensation operation".

[0077] iii. When the power monitoring device at port 1 measures that the input power of K1 is 0, the input power of K2 at port 2 can be transferred to A by adjusting the variable power divider (the output power of K2 measured by the power monitoring device at port 4 is 0 at this time) and provided to the variable power combiner (such as Figure 3 , can be adjusted Figure 6 Then, the power from A is provided to the downstream device of K1 (such as Figure 4, can be adjusted Figure 6 The output power of K1 at port 3 is determined by the measured value of the power monitoring device at port 3. This is called

[0078] "Fully compensated operation".

[0079] The above assumes that the output power level of each power source is the same, which is a reasonable assumption for large scientific devices that use the same klystron as microwave power source. At the same time, when adjusting the variable power synthesizer at any time, the phase shifter I should be used to make the phase difference between the two input powers at B and C 0° or 180° (such as Figure 6 As shown), the variable power combiner can successfully combine the two input powers.

[0080] In the simulation, the "normal operation", "partial compensation operation" when the K1 input power at port 1 drops by half, and "full compensation operation" when the K1 input power at port 1 drops completely to 0 are simulated and verified. The corresponding ratios of the K1 input power at port 1 to the K2 input power at port 2 are 1:1, 0.5:1, and 0:1 respectively (the K2 output power at port 4 is 1, 0.5, and 0 in the three cases). In the above three cases, the microwave power propagation direction obtained by simulation is shown in Fig. 9 .

[0081] from Fig. 9 It can be seen that the simulation results successfully verified the feasibility of the design scheme of "fast-switching microwave power source backup system". When the K1 input power at port 1 is only half or completely 0, the K2 input power at port 2 is successfully used for transfer compensation, and it does not affect the "normal operation" when the K1 input power at port 1 and the K2 input power at port 2 are both normal. Because it is impossible (and unnecessary) to simulate all situations of "the K1 input power at port 1 drops to all possible power levels", it does not prevent the above simulation results from successfully verifying the feasibility of the design scheme of "fast-switching microwave power source backup system".

[0082] Through the above theoretical derivation and simulation, the feasibility of arbitrary power ratio waveguide power distribution and synthesizer based on 3dB bridge is verified, and the theoretical formula results are completely consistent with the simulation results; by using 3dB bridge instead of magic T, the coplanarity of arbitrary power ratio waveguide power distribution and synthesizer is realized, which greatly reduces the system complexity and processing cost. At the same time, the feasibility of the design scheme of "fast-switching microwave power source backup system" is also verified in simulation, and a feasible switching method is given; through the combination of arbitrary power ratio waveguide power distribution and synthesizer, the K1 input power at port 1 ( Figure 6) partially drops or completely drops to 0, the K2 input power at port 2 ( Figure 6 ) Part or all of the power is transferred to K1. This greatly reduces the failure rate of large scientific equipment and ensures operating time.

[0083] Although the specific embodiments of the present invention are disclosed for the purpose of illustration, the purpose is to help understand the content of the present invention and implement it accordingly, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the best embodiment, and the scope of the present invention is subject to the scope defined in the claims.

Claims

1. A microwave power source backup system capable of rapid switching, characterized in that: The invention comprises at least one set of components, wherein the components include a variable power divider and a variable power combiner; The variable power synthesizer comprises a first phase shifter, a second phase shifter, a first 3dB bridge and an equal power synthesizer; The variable power divider includes a third phase shifter, a second 3dB bridge and an equal power divider; One output end of the equal power divider is connected to the input end of the third phase shifter through a waveguide, and the other output end is connected to the first input end of the second 3dB bridge through a waveguide; the input end of the equal power divider is used to receive the output power of the backup microwave power source and divide the input power into two outputs; the output end of the third phase shifter is connected to the second input end of the second 3dB bridge; the first output end of the second 3dB bridge is connected to the input end of the first phase shifter, and the second output end of the second 3dB bridge is used to connect to a downstream device; The first input end of the first 3dB bridge is connected to the output end of the first phase shifter via a waveguide, and the second input end of the first 3dB bridge is connected to the input port via a waveguide, for receiving the output power of the main microwave power source; the first output end of the first 3dB bridge is connected to the input end of the second phase shifter via a waveguide, and the second output end of the first 3dB bridge is connected to an input end of the equal power combiner via a waveguide; The output end of the second phase shifter is connected to the other input end of the equal power combiner via a waveguide, and the output end of the equal power combiner is used to connect to a downstream main device; The third phase shifter is used to adjust the phase of the input power, so as to control the output power distribution of the two output ends of the second 3dB bridge; The first phase shifter is used to adjust the phase of the input power, so as to control the phase difference of the input power at two input ends of the first 3dB bridge; The second phase shifter is used to adjust the phase of the input power and then output it to the equal power synthesizer; The equal power synthesizer is used for synthesizing two input powers and then outputting them.

2. The microwave power source backup system according to claim 1, characterized in that: When multiple sets of cascaded components are included, the output end of the power combiner in the upper stage of the component is connected to the input end of the power divider in the lower stage of the component.

3. The microwave power source backup system according to claim 1 or 2, characterized in that: The equal power divider is used to divide the input power into two power outputs with the same amplitude and phase.

4. The microwave power source backup system according to claim 1, characterized in that: The phase adjustment range of the first phase shifter can ensure that the input power phase difference between the two input ends of the first 3dB bridge is 0° or 180°, the phase adjustment range of the second phase shifter can ensure that the input power phase difference between the two input ends of the equal power synthesizer is 0°, and the phase adjustment range of the third phase shifter can ensure that the input power phase difference between the two input ends of the second 3dB bridge is -90°. Continuously adjustable from 0 to 90°.

5. A power switching method based on the microwave power source backup system capable of rapid switching according to claim 1, the steps comprising: In a normal working state, by adjusting the variable power distributor and the variable power combiner, the received output power of the standby microwave power source is fully provided to the downstream device, and the received output power of the main microwave power source is fully provided to the downstream main device; When it is monitored that the output power of the received main microwave power source decreases, the variable power distributor is adjusted to transfer a part of the output power of the backup microwave power source to the input end of the first phase shifter; the first phase shifter in the variable power synthesizer is adjusted to make the phase difference between the first input and the second input of the first 3dB bridge 0° or 180°, and the second phase shifter is adjusted to make the two power inputs of the equal power synthesizer have the same phase; When it is monitored that the output power of the received main microwave power source drops to 0, the variable power distributor is adjusted to transfer all the output power of the backup microwave power source to the input end of the first phase shifter; the first phase shifter in the variable power synthesizer is adjusted to make the phase difference between the first input and the second input of the first 3dB bridge be 0° or 180°, and the second phase shifter is adjusted to make the two powers input to the equal power synthesizer have the same phase.

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